The proposal work is part of an overall program in studying the biosynthesis, metabolism and function of hydroxy fatty acid sophorosides found in the yeast Candida bogoriensis and Torulopsis species. The two glucosyltransferases from C. bogoriensis that catalyze the synthesis of 13-sophorosyl-oxydocosanoic acid copurify by a variety of techniques, including affinity chromatography. The enzymes have been unstable to electrofocusing, but we hope to find the source of the instability in order to include this technique as part of the overall purification scheme. The immediate goals will then be to prepare quantities of purified enzyme to characterize chemically and kinetically, and to prepare antibodies to be used in studying the regulation of biosynthesis of these enzymes. Purification of similar enzymes from a Torulopsis species is also underway.